As a driving source of a wiper apparatus, a power window apparatus, a sunroof apparatus or the like provided in a vehicle, an electric motor actuated by a power source such as a battery mounted on the vehicle is normally employed. In order to adapt the electric motor to these apparatuses, it is necessary to decelerate rotation of the motor to predetermined revolution speed. Therefore, a deceleration mechanism is attached to the electric motor to be used for these applications, whereby the electric motor is unitized as one electric motor with a deceleration mechanism.
Such an electric motor normally has a case body formed into a bathtub shape so as to contain a deceleration mechanism, and an opening portion of the case body is covered with a motor cover. Further, there is known a motor in which a control board for controlling an operation of a motor main body and the like are contained inside the case body. In this case, a heat sink made of aluminum for emitting, to the outside, heat of an electronic part such as an FET mounted on the control board is fixed to the motor cover.
The motor cover is normally made of a resin, and the heat sink is fixed by insert molding to a resin portion of the motor cover, namely, the cover body. Further, in order to connect the control board and the motor main body, or connect the control board and a power source terminal, power-feeding terminals formed of copper plates or the like are fixed to the motor cover, and these terminals are also fixed to the motor cover by insert molding as shown in, for example, Patent Document 1. Namely, the heat sink and the respective terminals are arranged inside a mold die for molding the cover body, and then a melt resin material is cast in the mold die, whereby the heat sink and the terminals are fixed integrally to the resin-made cover body.
Meanwhile, in the case where the control board is arranged in the cover so as to oppose the heat sink, it is necessary to arrange, on the heat sink, a terminal part located on a control board side of the terminal connected to the control board. For this reason, a groove-shaped flow-in portion in which the resin material is cast at a time of the insert molding is provided in the heat sink, and a terminal part located on one side of the terminal is insert-molded so as to be arranged at this flow-in portion. Thereby, the terminal part on the control board side of the terminal is fixed to the flow-in portion by the resin material cast in the flow-in portion, namely, is positioned on the heat sink.
Patent Document 1: Japanese Patent Laid-Open Publication No. 2000-61947